As you can see from the picture below, the back of a standard denture ends just behind the hard bone in the roof of the mouth. They do this because they require as much surface area as possible to maximize retention and stability. In the case of people who gag, the back of the denture can be cut forward making the denture base look more and more like an arch. However, the more it is cut back, the less stable and retentive it will be!
Standard dentures are made for people who are already missing all their teeth. The top denture relies on "suction" to retain it, and the hardness of the underlying tissues for its stability. It generally takes 4 or sometimes more appointments to make a set of standard dentures.
The first appointment consists of an oral examination, sometimes X-Rays, and a set of impressions of the upper and lower edentulous (toothless) ridges (gums). These impressions are poured with plaster to form accurate models of the shape of the edentulous ridges. Other parameters are determined such as the shade, size and shape of the teeth that will be placed on the new dentures.
Upon occasion, the dentist
will recommend surgical alteration of the ridges to remove flabby tissue which will interfere with the stability of the denture
, and sometimes to alter the shape of the underlying bone allowing for a better fit. In most cases, such surgery is not essential, but can create the conditions for a MUCH more satisfactory final denture. Alterations like this are generally money well spent!
In some offices, the first set of impressions are used to make custom fitting impression trays for a second, more accurate impression. In this case, there will be one extra appointment in addition to the standard 4 mentioned above.